Today's high-end Internet Protocol (IP) router is capable of switching several million packets per second (PPS). When a real-time transport protocol (RTP) header compression function is turned on for Voice over IP (VOIP) applications, however, the switching rate of the IP router is reduced to 10,000 PPS, which is equivalent to less than two (2) full duplex T1 compressed VoIP traffic.
The only solution today is to use a faster central processing unit (CPU) on the IP router for RTP header compression and IP switching tasks. A two hundred megahertz (200 MHz) CPU on the Cisco.TM. 7500 router could increase the packet-processing rate to 10,000 PPS, which is still too slow for large scale VoIP applications. For example, process-switching the VoIP traffic with RTP header compression on an optical carrier (OC)-3 fiber link (155 Mega) requires at least seventy-five (75) high-end Cisco.TM. 7500 series routers.
Thus, there exists a need for a scheme that allows the IP router to transparently switch various multimedia content with a compressed RTP header at its native speed (million PPS) through the IP network, such as switching digitized VoIP network.